Some dinners wrap you up like a favorite quilt. This Turkey and Mashed Potatoes Casserole does exactly that. It’s cozy, it’s familiar, and it’s got that soulful “day after Thanksgiving” feeling without needing the actual holiday. Whether you’ve got leftover turkey waiting in the fridge or you’re just craving something hearty and homey, this casserole is your new go-to. It comes together with ease, bakes up golden and bubbly, and brings everyone to the table with a smile. Let’s get that oven preheated, friend.
Ingredients
Cooked Turkey: This is your base protein. Leftover roasted turkey, shredded or chopped, works like a charm. If you’re starting fresh, a simple baked turkey breast will do the trick.
Mashed Potatoes: These are the creamy crown of the casserole. Leftover mashed potatoes are ideal, especially if they’re already seasoned. Cold mashed potatoes spread easier if you soften them just a bit.
Butter: Melted into the filling and dotted on top for flavor and golden color. Butter makes it better, always.
Onion and Garlic: These build the base flavor. Sautéing them first adds a savory depth that ties everything together.
Frozen Mixed Vegetables: A shortcut to bring color, texture, and nutrition. Peas, carrots, corn, and green beans all shine here. No need to thaw before adding.
Chicken or Turkey Broth: This helps moisten the filling and bring everything together. Use homemade if you have it, or store-bought works just fine.
All-purpose Flour: Whisked into the butter and veggies to create a quick roux that thickens the sauce slightly.
Cheddar Cheese: Mixed into the filling or sprinkled on top. It melts into pockets of goodness that make every bite a treat.
Salt and Pepper: Always taste and adjust. The mashed potatoes and turkey might already be seasoned, so go gentle and build up if needed.
Step by Step Instructions
Start by preheating your oven to 375°F. Butter a medium baking dish, something around 8×8 or 9×9 inches, or grab a deep pie dish if that’s what you have on hand.
In a skillet over medium heat, melt two tablespoons of butter. Add chopped onion and cook until it’s soft and golden, about six minutes. Stir in minced garlic and let it bloom for a minute. Now whisk in the flour and let it cook for a minute or two until it forms a smooth paste. Slowly pour in the broth, whisking all the while to avoid lumps. Let it simmer gently until it thickens into a light gravy.
Take the skillet off the heat and stir in the chopped turkey and frozen vegetables. Fold in a handful of shredded cheese if you like, then season with salt and pepper. Spoon this savory filling into your prepared baking dish and spread it evenly.
Top the mixture with your mashed potatoes, spreading them gently with the back of a spoon or an offset spatula. Leave a few swoops and ridges if you want a toasty golden crust. Dot the top with a little butter or a sprinkling of cheese if you’re feeling indulgent.
Bake uncovered for 25 to 30 minutes, or until the edges are bubbling and the top is starting to brown. If you want extra crisp on top, switch on the broiler for a minute or two at the end, but keep a close eye so it doesn’t scorch.
Let the casserole rest for ten minutes before serving. This helps everything settle and slice up nicely. Spoon out generous helpings and watch them disappear.
Mistakes to Avoid
When making this Turkey and Mashed Potatoes Casserole, don’t skip seasoning. Taste the mashed potatoes and the filling separately before layering. Underseasoned casserole is a common slip and easily fixed with a little care. Also, don’t rush the baking time. That golden top and bubbling edges are part of the magic. Lastly, don’t overload the dish. If your pan is too full, it’ll bubble over in the oven. Leave a little space at the top or place the dish on a baking sheet just in case.
Pro Tips
If you’re making this right after a big holiday, chances are you’ve got more than just turkey and potatoes. Chop up leftover roasted carrots or Brussels sprouts and toss them into the filling for added flavor and texture. A spoonful of cranberry sauce swirled into the potatoes can give a sweet little surprise in each bite. If your mashed potatoes are a bit stiff from the fridge, stir in a splash of milk before spreading them on top. It’ll help them bake up smoother and creamier. And don’t shy away from a breadcrumb topping; mix breadcrumbs with melted butter and sprinkle it over the potatoes before baking for a golden crunch.
Serving Suggestions
This casserole is a full meal on its own, but if you want to round out the plate, a bright side salad with a vinegar-based dressing brings a lovely contrast. Something green like sautéed garlicky kale or steamed green beans would also work well. For a cozy dinner spread, serve this alongside a warm soup like butternut squash or creamy mushroom. If you’re leaning into comfort food, pour yourself a glass of apple cider or a mug of something warm and buttery.
Turkey and Mashed Potatoes Casserole
Equipment
- Baking Dish
- Skillet
- Spatula
Ingredients
Filling
- 2 cups cooked turkey shredded or chopped
- 1 onion chopped
- 2 cloves garlic minced
- 2 tbsp butter
- 2 tbsp all-purpose flour
- 1 cup chicken or turkey broth
- 2 cups frozen mixed vegetables peas, carrots, corn, green beans
- 1 cup cheddar cheese shredded, optional
- salt and pepper to taste
Topping
- 3 cups mashed potatoes leftover or fresh
- 1 tbsp butter for topping, optional
Instructions
- Preheat oven to 375°F (190°C). Grease a medium baking dish (8×8 or 9×9 inches).
- In a skillet, melt 2 tbsp butter over medium heat. Sauté chopped onion for 6 minutes until golden. Add garlic and cook for 1 more minute.
- Stir in flour to make a roux and cook for 1–2 minutes. Slowly whisk in broth to form a smooth gravy. Simmer until slightly thickened.
- Remove from heat. Stir in turkey, frozen vegetables, and half the cheese (if using). Season with salt and pepper.
- Transfer mixture to the prepared baking dish and spread evenly. Top with mashed potatoes. Dot with extra butter or cheese if desired.
- Bake uncovered for 25–30 minutes until bubbling and lightly browned. Optional: broil for 1–2 minutes for a crispier top.
- Let rest for 10 minutes before serving to allow it to set. Enjoy warm.
Notes
And if this cozy dish hits the spot, you might also love my low carb pizza casserole or this comforting broccoli and rice casserole with chicken. For something heartier, try the loaded baked potato with steak or an Italian-style baked chicken that’s perfect with any leftover sides.
Frequently Asked Questions
What’s the best way to reheat Turkey and Mashed Potatoes Casserole?
Use the oven if you want that crispy top again. Cover the dish with foil and reheat at 350°F for about 20 minutes, then uncover for the last five. If you’re just warming a small portion, a microwave works fine, but the texture won’t be as crisp.
Can I make this casserole ahead of time?
Absolutely. Assemble it fully, then cover and refrigerate for up to two days. When you’re ready to bake, take it out of the fridge while the oven preheats and add a few extra minutes to the baking time to account for the chill.
How do I thicken the filling if it looks runny?
If your mixture feels too loose after stirring in the broth, let it simmer a bit longer on the stovetop. It should gently bubble until thickened. A little extra flour or cornstarch slurry can help if needed, but go slow so you don’t end up with a gummy texture.
Can I use instant mashed potatoes?
Yes, you sure can. Just make them a little thicker than usual so they hold up as a topping. Add a touch of butter or sour cream to enrich them, and they’ll bake up beautifully.
More Than Just Leftovers
This isn’t just a recipe, it’s a second-chance supper. It’s what to do with leftover turkey and mashed potatoes when you’re tired of sandwiches and want something that feels new again. This easy turkey casserole with mashed potatoes brings together all the comfort of the holidays in a no-fuss, weekday-ready bake. And if you’re looking for more tasty ideas for leftover spuds, the folks at Serious Eats have a wonderful guide to Thanksgiving potato recipes that will spark even more kitchen joy.
So pull out that casserole dish, grab a spoon, and let’s turn those leftovers into something wonderful with this Turkey and Mashed Potatoes Casserole.
